:root {
  --ink: #16251e;
  --muted: #66736c;
  --green: #2f875c;
  --green-dark: #1c6644;
  --green-soft: #e9f4ed;
  --blue: #1674d1;
  --blue-dark: #0b5ca7;
  --line: #dce4df;
  --paper: #ffffff;
  --page: #f4f7f4;
  --shadow: 0 22px 64px rgba(31, 59, 43, .10);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 5%, rgba(47, 135, 92, .09), transparent 28rem),
    linear-gradient(180deg, #f8faf8 0%, var(--page) 100%);
  font-family: Pretendard, "Noto Sans KR", "Malgun Gothic", system-ui, -apple-system, sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

.site-header {
  min-height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 24px;
  background: rgba(255, 255, 255, .92);
  border-bottom: 1px solid rgba(220, 228, 223, .85);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: #1a2922;
  text-decoration: none;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .14em;
}

.brand-mark {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border-radius: 9px;
  color: white;
  background: var(--green);
  font-family: Georgia, serif;
  font-size: 18px;
  letter-spacing: 0;
}

.secure-label {
  color: var(--green-dark);
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
}

.secure-label span { font-size: 9px; margin-right: 5px; }

.page-shell {
  width: min(100%, 720px);
  margin: 0 auto;
  padding: 34px 18px 24px;
}

.support-card {
  padding: 42px;
  background: var(--paper);
  border: 1px solid rgba(220, 228, 223, .95);
  border-radius: 28px;
  box-shadow: var(--shadow);
}

.eyebrow {
  color: var(--green);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: .03em;
}

h1 {
  margin: 6px 0 12px;
  font-size: clamp(34px, 8vw, 48px);
  line-height: 1.15;
  letter-spacing: -.045em;
}

.intro {
  max-width: 590px;
  margin: 0 0 26px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.download-button {
  min-height: 84px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 15px;
  padding: 18px 24px;
  color: #fff;
  background: linear-gradient(135deg, var(--blue), #2189e7);
  border-radius: 18px;
  box-shadow: 0 14px 30px rgba(22, 116, 209, .22);
  text-decoration: none;
  text-align: left;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
}

.download-button:hover {
  transform: translateY(-2px);
  background: linear-gradient(135deg, var(--blue-dark), var(--blue));
  box-shadow: 0 18px 36px rgba(22, 116, 209, .28);
}

.download-button:focus-visible {
  outline: 4px solid rgba(22, 116, 209, .25);
  outline-offset: 4px;
}

.download-button svg {
  width: 29px;
  flex: 0 0 auto;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.download-button span { display: grid; }
.download-button strong { font-size: 18px; line-height: 1.35; }
.download-button small { opacity: .9; font-size: 12px; }

.file-note {
  display: flex;
  gap: 9px;
  align-items: flex-start;
  margin: 13px 4px 30px;
  color: var(--muted);
  font-size: 12px;
}

.check {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  margin-top: 1px;
  color: #fff;
  background: var(--green);
  border-radius: 50%;
  font-size: 11px;
  font-weight: 900;
}

.steps { display: grid; gap: 12px; }

.step {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 10px;
  padding: 21px 20px;
  border: 1px solid var(--line);
  border-radius: 17px;
}

.step-accent { border-color: #b9d7c6; background: #fbfefc; }

.step-number {
  color: var(--green);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: .05em;
}

.step h2,
.privacy-box h2 {
  margin: 0 0 3px;
  font-size: 16px;
  line-height: 1.45;
}

.step p,
.privacy-box p { margin: 0; color: #536159; font-size: 14px; }

.privacy-box {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 12px;
  margin-top: 18px;
  padding: 20px;
  background: var(--green-soft);
  border-radius: 17px;
}

.privacy-box svg {
  width: 29px;
  fill: none;
  stroke: var(--green-dark);
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.privacy-box h2 { color: var(--green-dark); }

footer {
  width: min(100%, 720px);
  margin: 0 auto;
  padding: 8px 28px 42px;
  color: #78827c;
  font-size: 11px;
  line-height: 1.75;
}

footer p { margin: 5px 0; }

@media (max-width: 600px) {
  .site-header { padding: 0 16px; }
  .secure-label { display: none; }
  .page-shell { padding: 24px 10px 18px; }
  .support-card { padding: 28px 24px; border-radius: 23px; }
  .intro { font-size: 16px; }
  .download-button { min-height: 78px; padding: 16px 17px; border-radius: 16px; }
  .download-button strong { font-size: 16px; }
  .step { grid-template-columns: 40px 1fr; padding: 19px 17px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}